1. Field of the Invention
The present invention relates to composite grains of tourmaline, a production method thereof, and an apparatus using the tourmaline composite grains for example to supply wash water.
2. Description of Prior Art
Tourmaline is a mineral represented with a chemical formula, NaX.sub.3 Al.sub.6 (BO.sub.3).sub.3 Si.sub.6 O.sub.18 (OH).sub.4. It is divided into iron tourmaline (X=Fe), lithia tourmaline (X=Li+Al) and magnesia tourmaline (X=Mg), and mixed crystals thereof are generated. Usually tourmaline including iron tourmaline as a main component is available most. In the crystal structure, ions of Na, Li, Al, Fe etc. are arranged in a network structure of Al.sub.2 O.sub.3 --B.sub.2 O.sub.3 --SiO.sub.2. As to electric properties of tourmaline, piezoelectricity and pyroelectricity were found in 1980, and it is known to have permanent electric poles. These properties vanish at about 1,000.degree. C. Tourmaline is an infrared rays radiator, and the wavelength of infrared radiations is equal to or larger than 10 .mu.m at room temperature.
Tourmaline is used for example to remove electrostatic charges by mixing it into synthetic fibers, using electrical properties thereof and to subject water itself to surface activation in water processing. Other various uses have also been proposed.
A tourmaline particulate as described in Japanese Patent laid open Publication 3-118894/1991 comprises tourmaline fine powders and a binder (or highly electrically insulating ceramics), where the tourmaline fine powders are embedded in the ceramics. The amount of the tourmaline fine powders in the particulates is about 5-10% of the entire amount, in order to maximize the number of tourmaline electric poles existing on the surface of the particulates while not canceling the opposite charges by contact to each other. However, such prior art tourmaline particulates, for example, do not have a satisfactory degree of surface activation effect. Therefore, it is desirable to solve various problems in order to use tourmaline in various uses effectively.
In general, a structure such as an automobile, a railroad train, an airplane or an outer wall of a building exposed to an outdoor environment is washed to remove dirt due to adherence of dust, oil or mud. When such a structure is washed, a detergent or a drug is used to improve washing performance. For example, an automobile is washed to remove dirt adhered on the body thereof, and it is waxed thereafter to improve its luster and to suppress adhesion of dust or the like.
When washing with a detergent or a drug is repeated, however, the surface of the structure is changed in quality or deteriorated by the detergent. For example, the coating on the body of an automobile is deteriorated and loses its luster. Further, because a large amount of detergent is used in the washing of large structures, the water quality in a river, a lake, a pond or an inland sea becomes worse if the detergent is not processed sufficiently in sewage systems and the like. It is also a problem that water resources are used wastefully, especially in the times of water shortage.
Further, underground water or well water is often used in the washing of such structures because of the low cost. In such a case, it is a problem that green moss grows on the surface of the structures. Therefore, it is desirable that structures are washed effectively while keeping luster of the surface thereof.